Washington state law allows landlords to collect a pet deposit as part of the rental agreement. See the most common pet addendum examples to include in a rental lease agreement.Here's a sample Pet Agreement for renters with guidelines for requirements, responsibilities and how to manage issues. A pet addendum gives permission to allow the tenant to have pets on the rental property. It requires the tenant will be responsible for their pet(s). Residential Rental Forms. These policies include "guest pets. Download a pet addendum to a lease template to allow a tenant to have a pet in a rental property and establish the rules they must follow. 5) Tenants agree to clean up after their pet and to dispose of their pet's waste properly and quickly. A pet lease addendum is added to a residential lease agreement to outline the rules for keeping pets on the rented property.